package edu.zzuli.common;

/**
 * Created by Chen-D.W on 2018/1/7.
 */
public class Single {

    private static Single s=null;

    private Single(){}

    public static Single getInstance(){
        if(s==null){
            synchronized (Single.class){
                if (s==null){
                    s=new Single();
                }
            }
        }
        return s;
    }
}
